“When you kill innocent children — innocent babies — babies — little babies with a chemical gas that is so lethal, people were shocked to hear what gas it was, that crosses many, many lines. Beyond a red line, many, many lines,” Trump said, according to CNN.

The U.S. missile strike could have deep implications with Russia already condemning Trump’s actions.

Here’s five facts you need to know about the conflict in Syria.

The current conflict started out as peaceful protests.

The protests were part of what is known as the Arab Spring. In December 2010, protests in Tunisia launched the peaceful protests against autocratic regimes that spread to several other Middle Easter countries, including Syria.

In March 2011, the peaceful protests turned violent after Syrian President Bashar al-Assad began a violent crackdown. That lead to rebels organizing to resist al-Assad. Syrian army defectors aligned themselves with many civilians and formed the Free Syrian Army. The violent conflict that took hold in Damascus and the ancient city of Aleppo has spread to many parts of the country.

And now the conflict is growing ever more complicated with the addition of grops such as ISIS and al-Qaeda. many experts believe the Syrian war is also a proxy war between Russia and the United States, reminiscent of the Cold War.

Who is Bashar al-Assad?

Syria’s current leader took control in 2000 following his father’s death after a three decade reign. He is trained as a doctor and was not in line to be the next leader but his older brother died in a car crash.

He was educated in London and gave western governments hope that he would be more moderate. He started down the path, making some reforms before shifting.

How many people have died in the conflict?

The United Nations estimates that more than 400,000 people have died during the bloody civil war. Christy Delafield, a senior communications officer at Mercy Corps, one of the largest humanitarian aid groups helping hundreds of thousands of Syrians with food and other basic necessities, said some of the remaining schools have taken to holding classes literally underground to protect children from airstrikes.

The use of chemical weapons that Trump says prompted the U.S. military response is not the first time the outlawed weapons have been used in Syria.

“The conflict has been unpredictable and continuously changing. There have been air strikes and aerial bombings and there are issues with protection of aid workers. We’ve seen hospitals hit,” Delafield told NewsOne in an interview Friday.

The Syrian war has caused the largest refugee crisis since World War II

There are an estimated 5 million Syrian refugees living outside of Syria, many in neighboring countries. Turkey has 3 million Syrian refugees, Lebanon has 1 million, while there are 700,000 refugees in Jordan and 230,000 in Iraq, which is experiencing it’s own difficulties. Inside Syria, there are estimates that 6 million people have fled their homes to find safety. Syria’s pre-war population was approximately 22 million people.

“Half the population is on the run. Half have fled for their safety and their family’s safety,” said Delafield. “For civilians the front lines are moving around them. They have fled many times but there isn’t a safe place in Syria. The humanitarian crisis is causing massive problems. Aid organizations are straining to meet the needs of millions of people.”

In Lebanon and Jordan, the World Food Program has had to cut the amount of aid it is able to give. Water infrastructure, medical facilities and schools are stretched to the limit and there are tensions between the resettled Syrian refugees and the native populations where they are being placed.

What can Americans do?

Delafield said cash assistance to organizations such as Mercy Corps which is on the ground in the region is the best way to help Syrians now due to the overwhelming need.

“There isn’t enough aid to support the people in need and there have been cuts to the food aid,” she said.

The United States is also set to cut its foreign aid budget which currently makes up 1 percent of the U.S. budget. “We are concerned about the effect those cuts would have on Syria. We encourage people to reach out to their elected officials and support more foreign aid,” said Delafield.

But there is only one thing that will really help the Syrian people.

“The only thing that will really put an end to the suffering of the Syrian people is an end to the conflict,” Delafield added.